Lumbar Disc Herniation Influences Gait
Muscle weakness, reduced motor function, and change in walking capacity are potential complications resulting from a herniated nucleus pulposus (HNP) in the lumbar intervertebral disc. Other clinical symptoms include pain, sensory changes and impaired reflexes, although the specific effects of disc herniation on muscle function during gait have not been adequately documented in the literature.
This study served to assess "...whether changes in the moments produced at the ankle and knee joints during walking reflect the neurologic level of a herniated nucleus pulposus." Physical examination and kinematic gait analysis were performed on 16 patients who were scheduled for HNP surgery.
Eight patients had L4-L5 HNPs, and eight had L5-S1 HNPs. Three components of the external moment at the ankle and knee were computed; peak magnitudes of specific components of the external moments were compared with a matched control group of 16 patients; and findings presented as summary:
* Preoperative gait analysis identified functional muscle deficits about the ankle and foot, relating to the level of the herniation.
* Reduced external ankle plantarflexion moment was found in patients with L4-L5 and L5-S1 HNP.
* Reduced external ankle dorsiflexion moment was found in patients with L5-S1 HNP, but not in those with HNPs at the L4-L5 level.
* Kinetic measurements can assist in understanding the functional limitations associated with specific levels of a herniation.
This is an interesting study that scientifically evaluates a basic assumption of many health care providers: There is muscle function during HNP. The quantifications of this relationship by the authors have several potential clinical manifestations.
Morag E, Hurwitz DE, Andriacchi TP, et al. Abnormalities in muscle function during gait in relation to the level of lumbar disc herniation. Spine
, April 1, 2000:25(7), pp829-33.